Search

Your search keyword '"Niggli, Nadja"' showing total 17 results
Start Over Author "Niggli, Nadja"
Sorry, I don't understand your search. ×
17 results on '"Niggli, Nadja"'

4. Synthesis of 1,2‐Dialkylaminoethers via Photoredox Catalyzed Hydroamination of Vinylethers.

Author

Niggli, Nadja E., Bienewald, Frank, Kirchner, Hülya, Shevchenko, Grigory A., Hashmi, A. Stephen K., and Schaub, Thomas

Subjects
*HYDROAMINATION, *ABSTRACTION reactions, *VINYL ethers, *SECONDARY amines, *ALKYL ethers, *AMINATION, *HOMOGENEOUS catalysis, *DISULFIDES
Abstract

Herein, a general applicable method for the atom‐economic catalytic construction of a broad range of 1,2‐dialkylaminoethers is presented. By taking advantage of an elaborated protocol for the photocatalyzed anti‐Markovnikov selective hydroamination of nonactivated alkenes, a series of 1,2‐dialkylaminoethers was accessed by reacting readily available vinyl ethers with secondary alkyl amines. It was demonstrated that the reaction can be performed at low catalyst loadings while the commonly employed triisopropylbenzene thiol Hydrogen Atom Transfer (HAT)‐catalyst was replaced by an easier accessible mesityl thiol. Furthermore, the inexpensive and readily available diphenyl disulfide was proven as suitable HAT‐catalyst alternative for the efficient hydroamination of simple vinyl ethers. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

5. N-Heterocyclic Carbenes in Pd0-Catalyzed C(sp3)–H Activation

Author

Niggli, Nadja Elena, Baudoin, Olivier, Ward, Thomas R. R., and Albrecht, Martin

Abstract

The direct functionalization of C(sp3)–H bonds by transition metals has emerged as an efficient strategy in the streamlined synthesis of valuable molecules. However, translating this reactivity to an asymmetric transformation has thus far been only moderately successful. A limited array of motifs was accessed in high enantioselectivity by Pd0-catalyzed C(sp3)–H arylation during the course of the last 10 years. In this thesis, we aimed to address this shortcoming with the development of new asymmetric methods for the construction of enantioenriched cyclic products. In the first project, different indanone products were synthesized in excellent yields and moderate enantioselectivity by C(sp3)–H arylation. Strikingly, IBiox-type ligands generally exhibited an exceptional reactivity and product selectivity compared to other classes of ligands. In addition, the IBiox ligands performed best in terms of enantioinduction, but still with limited stereoselectivity. Based on these findings, new IBiox-derived NHC ligands were designed with the intention to improve their stereoinducing properties in the envisioned C(sp3)–H arylation transformation. This plan was pursued in a second project wherein a new IBioxtBuMe4 ligand was synthesized and successfully employed in the challenging desymmetrization of enantiotopic protons in the construction of indanes. In addition to this, the synthetic sequences towards two further ligands were initiated and are now close to completion. In parallel, new carboxylate bearing NHC-complexes were designed, synthesized, and characterized. Careful experimentation and analysis of the data revealed the delicate nature of these complexes which accounts for their unsatisfactory performance in the envisioned reactions. Interestingly, during the course of these investigations, a β-lactam product was identified arising from a new 1,4-Pd shift and subsequent C(sp3)–C(sp3) bond formation. This new reactivity was exemplified in the synthesis of biologically interesting β-lactams. In addition, mechanistic studies were performed to disclose the nature of this transformation. IBiox-type ligands showed a superior product selectivity for this novel reactivity and proved to be key to its success.

Published
2022

6. Synthesis of Anilides by Aminolysis of Unactivated Esters using MnCl2 in Combination with strong Bases as Catalyst.

Author

Niggli, Nadja E., Vollgraff, Tobias, Winter, Christian, Slavcheva Petkova, Desislava, Benson, Stefan, Götz, Roland, Hashmi, A. Stephen K., and Schaub, Thomas

Subjects
*ANILIDES, *ESTERS, *PLANT protection, *ANILINE
Abstract

Anilides are often found in pharmaceuticals and active ingredients in crop protection. Although of great interest, the atom‐ and step economic formation of the amide bond between a less nucleophilic aniline with an acid or ester remains still a major challenge. Herein, we report an aminolysis of aromatic and alkyl esters with anilines catalyzed by a readily available catalytic system comprising of an earth‐abundant Mn‐salt in combination with an inexpensive base. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

7. PCC Christmas Symposium Basel

Author

Baiyoumy, Alain, primary, Coats, John, additional, D'Addio, Adriano, additional, Huber, Annika, additional, Jauslin, Werner, additional, Kress, Charlotte, additional, Niggli, Nadja, additional, Peng, Jiaming, additional, Persiani, Giacomo, additional, Pfund, Björn, additional, Rieder, Pascal, additional, and Chimisso, Vittoria, additional

Published
2022
Full Text
View/download PDF

9. Christmas Symposium Basel, December 4, 2020

Author

Joss, Daniel, primary, Reznikova, Ksenia, additional, Pfund, Björn, additional, Niggli, Nadja, additional, Murawska, Gosia M., additional, Miarzlou, Dzmitry A., additional, Meyer, Claire E., additional, Chimisso, Vittoria, additional, Baiyoumy, Alain, additional, and Rieder, Pascal, additional

Published
2021
Full Text
View/download PDF

12. Swiss Science Concentrates

Author

Baumgartner, Yann, primary, Niggli, Nadja, additional, Savary, David, additional, Thesmar, Pierre, additional, and Baudoin, Olivier, additional

Published
2020
Full Text
View/download PDF

13. Christmas Symposium Basel December 6, 2019

Author

Joss, Daniel, primary, Vallapurackal, Jaicy, additional, Baiyoumy, Alain, additional, Chimisso, Vittoria, additional, Christoffel, Fadri, additional, Herr, Patrick, additional, Meyer, Claire, additional, Miarzlou, Dzmitry, additional, Murawska, Gosia, additional, Niggli, Nadja, additional, Reznikova, Ksenia, additional, Urosev, Ivan, additional, and van Gerwen, Puck, additional

Published
2020
Full Text
View/download PDF

14. Swiss Science Concentrates

Author

Baumgartner, Yann, primary, Niggli, Nadja, additional, Savary, David, additional, Thesmar, Pierre, additional, and Baudoin, Olivier, additional

Published
2019
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results